Sawm in Arabic.
Fasting means that a person may. in obedience to the command of Allah, refrain, from the time of Azan for dawn prayers up to dusk, from nine things which will be mentioned later.
Useful information: It is not necessary for a person to pass the intention to fast through his mind or to say that he would be fasting on the following day. Rather it is sufficient for him to determine that in obedience to the command of Allah he will not perform, from the time of Azan for dawn prayers up to dusk, any act which may nullify the fast. And in order to ensure that he has been fasting throughout this time he should refrain, for some time before the Azan for dawn prayers, and, for some time after sunset from acts which nullifies a fast.